Relay actuating device for automatic phonographs



A. MULLANEY 9 @9251 RELAY ACTUATING DEVICE FOR AUTOMATIC PHONOGRAPHS Filed Aug. 24, 1949 Fig l Mofion Converting Mechanism Direction of 55 Movement AA Direction of 8 Move em RALPH AMULLANEY INVENTOR.

HIS ATTOR Y Patented Aug. 29, 1950 RELAY ACTUATING DEVICE FOR AUTOMATIC PHONOGRAPHS Ralph A. Mullaney, Elmwood Park, 'Ill., assignor to Zenith Radio Corporation, a corporation of Illinois Application August24, 1949, Serial No. 112,014

6 Claims. 1

This invention relates, in generahto a novel relay actuating device for a record changer and more particularly to one that is responsive to reverse movement of a tone arm for initiating a record changing cycle.

In a record player, in order that wearofthe record disc grooves and of the stylus point may be minimized transducer unitshave been developed which may be utilized at a relatively light stylus pressure as compared with prior devices. One of the problems which arise as a result of reduced stylus pressure is that of insuring proper tracking of the stylus in the grooves, This is understandable since, as the stylus pressure is decreased, any force which impedes progress of the tone arm causes the stylus to ride up the side and slip out of the groove.

One of the forces which hinders progress of the tone arm is produced by the mechanism for initiating a record changing cycle. Prio mechanisms utilized ior'this purpose require 'a relatively heavy stylus pressure. Hence, at low stylus pressures, tracking of the stylus in the grooves is materially impaired before a sufiicient force can be developed with which to actuate the initiating mechanism, and operation may be erratic.

It is an object of this invention, therefore, to provide a novel relay actuating device for a record changer which requires but a small operating force for initiating some other operating function, such as a record changing cycle.

In accordance with the invention, the relay actuating device is utilized in a, record changer including a tone arm and a relay actuated control circuit. The devi e comprises an elongated cam track and.- a pendulum-like member including a contact-making portion disposed at the free end, a cam-follower portion for engaging one surface of the cam track to support the pendulum for movement therealong, and a braking portion for engaging the opposite: surface of the cam track but normally maintained out of contact therewith. The actuating device also includes a first driving member actuated by the tone arm for engaging the pendulum in the vicinity of the cam-follower portion to advance the. pendulum in one direction along the track when the tone arm is displaced in a given direction. The relay actuating device further includes a second driving member having a contact-making portion normally out of engagement with the contactmaking portion of the pendulum. The second driving member is mechanically coupled to the tone arm so that in response to displacementof the tone arm in a direction reverse to the given direction, the second membe engages the pendulum to extend the relay-circuit through both of the contact-making portions. Simultaneously the pendulum is pivoted to bring the brake portion into engagement with the cam track. Thereby, reverse movement of the pendulum along the track is impeded and firm engagement of'the contact-making portions is secured.

The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention itself, both as to its organization and manner of operation, together with further objects and advantages thereof may best be understood by reference to the following description taken in connection with the accompanying drawing in which:

Fig. l is a functional diagram, partly in block, of a record changer including a relay actuating device embodying the present invention shown. in perspective;

Fig. 2 is a sectional view taken along 1ine'2- 2 of Fig. l with one of the elements of Fig. 1 distorted and showing the relayactuating device in one condition of operation;

Fig. 3. shows the device of Fig. 2 in. another condition of operation.

Referring to Fig. l, the record changer l0, there represented, includes a mounting. base, and a turntable 12 supported for rotation thereon. A centralspindle 13 extends upwardly from turntable l2 and includes a shelf portion M which conjointly with a side shelf l5 supportedby a sidepost it forms a record storage magazine for a stack of record discs such as H. One ,of the records ll from stack I! is shown in position for. playing on turntable 12.

.A driving motor l8 having a driving shaft- I9 is coupled with the inner side of rim 20 of turntable 12 through an idler'gear 2|. Drivingmotor I8 isof the synchronous, constant speed variety and the rotational speed of turntable I2 is predetermined by the diameters of shaft l9 and rim 2!! in a well known manner.

A tone arm 22 having a stylus and transducer unit. 23 is supported for pivotal movement about a horizontal axis by means of a hinge having companion upper and. lower portions 24 and 25. Tone arm 22 further is supported for rotation about a vertical axis by means of a vertical shaft 26 afiixed at one end to hinge portion 25 which rests upon a bearing block 21 secured to base member I l. Tone arm 22 thereby is supported so that the stylus of' element 23 is engageable generally well known, and records may be] dropped successively from stack I? by a single rotation of shaft 29 in a conventionalmanner.

Shaft 29 is connected mechanically through a I pair of gears 3! and 32 and through a shaft 33, to a motion-converting mechanism 34. This mechanism includes the means for converting the rotary motion of the turntable into the var-v ious movements necessary to perform a record changing cycle and its operating details will be more fully explained hereinafter. Motion-converting mechanism 34 is coupled through a shaft 35 with a clutch 35 which may be of any well known variety. Clutch 36 is connected, through a-shaft 31, a driven gear 38 and a driving gear 39 in the designated order, to turntable 52 by extension thereof. The clutch 36 provides a selective mechanical coupling between turntable l2 and mechanism 34.

Motion-converting mechanism 34 is coupled with an actuating bar 4! which is supported for vertical movement in the vicinity of tone arm 22 and is in incipient engagement with a projection 42 of upper hinge portion 24. anism 34 is coupled with shaft 26 by means of a link 43. Shaft 25, in turn, is coupled with a relay actuating device 44 embodying the present invention and which will be more fully described hereinafter. Device 44 is coupled electrically with a rela actuated control circuit 45 including a source of potential 46'connected toone terminal of a relay 47 through a conductor 48. The other terminal of relay 4'! is connected to one terminal of device 44 by a conductor 49. A conductor 50 is connected to a brush contact 50 bearing upon shaft 25, which forms the other terminal of device 44, and the relay circuit is completed by the connection between conductor 50 and the potential source. Relay 4'! is positioned to actuate clutch 36 by means of an actuating lever 5|.

Neglecting for the moment the operation of the: relay actuating device 44, the apparatus above described comprises, in general, a conventional record changer. The operation of such a record changer is well understood so that a detailed description is unecessary. In brief, however, a record ll is rotated for playing on turntable I2 and stylus 23 tracks in the grooves thereof. As the playing progresses'tone arm 22 is'rotated about the vertical axis of shaft 26 and tone arm'22 is displaced in a given direction whereby stylus 23 progresses into the plane of the drawing of Figure l.

Movement in the given direction continues untilthe eccentric grooves, positioned toward the center of the disc, are engaged by stylus 23. such grooves impart a motion to tone arm 22 in a direction reverse to the given direction. By meansof shaft 26, reverse movement is imparted to relay actuating device 44 which completes relay circuit 45 and an electromagnetic field set up by relay4l displaces lever 5|. Lever 5| actuates clutch 36 to complete a driving connecs Further, mech- 4 tion between turntable l 2 and motion converting mechanism 34.

Mechanism 34 converts the rotational movement of turntable l2 into motion of the various elements as follows: Actuating bar 4! is dis-placed upwardly and engages projection 42 of tone arm 22 which is pivoted about the horizontal axis of hinge 24, 25 and stylus 23 is carried from engagement with the grooves of disc ll. Link 43 is rotated and carries shaft 25 t0- getherwith tone arm 22 in a rotational direction to bring the tone arm outwardly from the center of disc 11 and beyond the edge thereof. Ejector lug 2B is rotated to displace the lowermost record from stack I l and free its centering opening from shelf i l of spindle l3 and its outer. extremity from shelf Hi to drop this disc atop disc ll. Shaft 26 then is rotated to carry tone arm 22 to a position wherein stylus 23 is above the starting grooves of the new record and ejector lu 28 is returned to its rest position. Finally, actuating bar 4! is lowered and stylus 23 engages the startin grooves of the new record.

Referring now more particularly to that portion of Fig. l embodying the present invention, relayactuating device 44 comprises an elongated, arcuate cam track 52 spaced about shaft 25 and defining an arc of a circle equidistant at all points from the vertical axis thereof. Track 52 is constructed of an electrically conductive material and in a particular embodiment has a circular cross section of predetermined diameter.

A U-shaped, pendulum-like member 53 includes aipair of circular openings 54, 55 individually disposed near one end of each of leg portions 56 and 5'! thereof and near the portion of pendulum 53 which connects the leg portions. Each of openings 54 and 55 has a cross-sectional diameter greater than that of track 52. As shown in Fig. 2, upper extremities 54' and 55 of openings 54 and 55 respectively, constitute a cam-follower portion of pendulum 53 for engaging the upper surface 58 of track 52 and support the pendulum for movement therealong. Since the openings are somewhat larger than the track, this'sliding movement is not impaired by frictional forces if a pendulum of light weight material, such as aluminum is employed. The lower extremity 54" of opening 54 constitutes a braking portion for engagin the opposite or lower surface 59 of cam 52 but is maintained normally out of contact therewith. Pendulum 53, being of aluminum in a particular example, is electrically conductive and includes a contactmaking portion 68 disposed at the free end of leg portion 57.

- .A first driving member 5| is affixed to shaft 28, is rotatable with the tone arm about its vertical axis and extends from the shaft for a length substantially equal to the distance between the shaft and track 52. Driver Si is actuated by the tone arm for engaging the pendulum 53 in the vicinity of the cam-follower portion of opening 55 at the inner side of leg portion 51. Hence, the pendulum 53 is advanced in one direction along track 52 when tone arm 22 is displaced in the given direction, with stylus 23 moving into the plane of the sheet of Fig. 1. Member Bl preferably is constructed of an electrically insulating material. An electrically conductive, second driving member 62 is afiixed to shaft 26 at a distance from driver 6i approaching the length of a leg portion of pendulum 5.3. Driver 62 is substantially aslong asdriver 6], but is displaced angularly relative thereto on shaft 25: Member 62 hasj a contactmaking portion 63" remotely positioned relative to shaft 26 and normally out of'enga'ge; ment with contactmaking portion; 60. of pen dulum 53. Since driver 62 is' coupled.v mfich anically with tone arm 22, in response to displacement of the tone arm ina direction reverse to:

the given direction, membe 62 engages, through contacts 63and 60, the opposite side of the leg portion 51 as does member Bl. Relaycircuit 45 thereby is completed through track 52, pendulum;

53, both of the contact-making portions 55 and 63, and member 62. Simultaneously 'the pen dulum 53 is pivotedto bring "the brake portion 54" into engagement with surface 59 of track 52 to impede reverse movement of the pendulum along the track. This secures 'firm engagement of contact-making portion 60; and 63.

In Fig. 2, showing a' cross-sectional View of pendulum 53, track 52 is distorted from its arouate shape to lie in the plane of the sheet in order track 52 and inasmuch as member 52 rotates with" tone arm 22, it'is normally out of engagement with leg portion 51.

In Fig. 3 the condition oi operation shownis that wherein tone arm 22 is displaced in a direction reverse to the given direction. Member 6 is removed from engagement with leg portion i and driver 52 is engaged with the lower extremity thereof through contact portions 60 and 53. A turning moment is produced about extremity 55 of opening 55 since the weight of leg portion 56 is not sufficient to counter the force so imposed. The pendulum 53 is pivoted about surface 55' and the lower extremity 54" of opening 55 is carried into engagement with the lower portion 59 of cam 52. brake is formed which impedes movement'of pendulum 53 in the direction of arrow B. The braking issufiicient to secure firm engagement of contact portion 55 and 63 but not of a magni-" tude to arrest movement in the direction of arrow B.

After being initially tilted, pendulum 53 is sustained in this position throughout a record changing'cycle and is carried to one end of track 52"corresponding"to the position of tone arm ZZ'for engaging the starting'grooves of a new record; As stylus23 of tone arm 22 tracks in" the grooves'of the new record, driver62 is dis-' engaged from leg portion 5'I'and driver 6! is engaged therewith and the cycle aforedescrib'ed' is repeated.

As has been pointed out hereinbef ore, a very small driving'force is required for displacing the pendulum along the cam track. Furthermore,

it may' be seen that the tilting force, for the pendulum, which is app-lied at the lower extrem It is apparent that a 6. g the tracking of a tone stylus V la recordldis'c. "Whileaparticulalr embodiment of the present invention has'been shown and'described, it will be obvioustothose skilled in the art that changes eri l r.v im

-' and modifications may be made without departnv tio ingjfrjom'thisinvention in its broader aspects, and, therefore, the aim in the appended claims is'to cov r; all such changes and modifications asffallwithin the'true spirit and scope of this Imam:

1. Inffa recordchanger including a tone arm and aifrelay actu'ated control circuit, a relay actuating device comprising: an elongated cam track; a'pendulum-like member including a conengagingithe'opposite surface of said cam track dulum, said second driving member being mechtact-making portion disposed at the free end, a

cam-,follower portion for engaging one surface of said cam'tracktosupport said pendulum for movement .therealong, and a braking portion for bilt' norm'ally maintainedout of contact therewithj'a first drivin'gmember actuated by said to'rie arin"for engaging said pendulum in the vicinity ot said camfollower portion to advance saidpendulum in one direction along said track when said't'one arm is'displaced in a given direction'; and ,a seeond driving member having a contactrnaking portion normally out of engagement with"said -contact-making portion of said pen- 'said', relay en-0 11a through both ofsaid contactnriaking portions and simultaneously to pivot sa'id pendulum to bring said brake portion into engagement with said cam track thereby to impede reverse movement of said pendulum along said track and secure firm engagement of said contact-making portions.

2; In a record changer including a tone arm rotatable aboutavertical axis and a relay-actuated'control circuit, a relay actuating device com-- prising: an elongated cam track defining an arc ofacirclaequidistant at all points from said Vertical axis; a pendulum-like member including a contact making portion disposed at the free end, -a cam-follower portion for engaging one surface of said cam track to support said pendulum for me vement therealong, and a braking portion forengagingthe opposite surface of said cam track but normally maintained out of contact therewith a first driving member rotatable with sa'idtoue arm about said axis for engaging said pendulum in thevicinity of said cam-follower portion to advance said pendulum in one direction along said track when said tone arm is displaced inia given direction; and a second driving member having a contact-making portion normally out oi engagementwith said contact-makingportionpf said pendulum, said second driving member being mechanically coupled to said tone arm so that in response todisplacement of said tone arm in a direction reverse to said given direction said secondmember engages said pendulum toextend said relay circuit through both of said contact-making portions and simultaneously to pivot said pendulum to bring said brake portion intoengagement with said cam track thererotatable with a;vat,ljalrgshan,angina-tau ated control circuitja relay actuatingdevice com prising: an elongated, arcuate cam track spaced about said shaft; a' pendulum-like memberin eluding a contact-making portion disposedat the 5" free end, a cam-follower portion forengaging one surface of said camtraclijosupport Saidpe'ndu luinfor movementtherealong, and a bra injg por; tion for'engaging' the opposite ,surfacefoffsaid cam track but normally maintained out jof-Jcon-. tact therewith; a first driving member supported by said shait forengaging said penduium in the vicinity of said'jcamfollow'er portion to advance said'pendulum in one direction alo 'g said traclt when S e i i d la e in agive i d tion; and a second driving member havingaco n tact-making portion normally out of engagement with said contact-making portion of said pendulum, said second drving member being supported by said shaft but angularly displaced relative to, said first driving member so that in response to displacement of said tone 'armin a directionrever'se to said given direction said second member engages said pendulum to extend said relay cir-' cult through both of said contact-making portions and simultaneously to pivot saidpendulum to bring said brake portioninto engagement with said cam' track therebyt impede reverse movement of said pendulum along saidjtrack and secure firm engagement of "said contact-making portions} a V f i w In a rec'ord changer including:a{tone arm and a relay actuated control circuit, a relay actuating device comprising: an elongated cam track having predetermined cross-secti nal dimensions a U-shaped, pendulum-like "membellincluding a pair of openings having cross-sectional dimen sions largerthan those of said cam track indiv'idually disposed near one end of each" of the legportions thereof, the upper extremitiesoi saidopenings *constituting'a camtion for engaging one surfaceof sa to support said pendulum for movement therealong and theilower extremity of one'of said openings forming a braking portion-for engaging the opposite surface of said cam track butnormally "maintained out of contact therewith, and; including a contact-making portion'disposed at the free end of one of said leg portions; 2. first driving member actuated by said tone'arm for engaging said pendulum in the vicinity of said cam-follower portion to advance saidpendulu n in one direction along said track when said tone arm is displaced in a given direction; and a second driving member having a'contact-making portion normally out of engagement with said contact-making portion of said pendulum, said second driving member being mechanically coupled to said tone arm so that in response to dise placement of said tone arm in a direction reverse to said given direction said second member engages said pendulum to extend said relay circuit through both of said contact-making portions and simultaneously to pivot said pendulum to bring said brake portion into engagement with said cam track thereby to impede reverse movement of said pendulum along said track and secure firm engagement of said contact-making portions.

-5; In a record changer including a tone arm and a relay-actuated control circuit, a relay actuating device comprising: an elongated cam track having predetermined cross-sectional dimensionsf a U-shaped,. pendulum-like member including a pair of openings having cross-sectional dimensions larger thanthose of said cam track individually disposed near one endof each of the leg portions thereof, the upper extremities of said openingsconstituting a cam-follower portion for engaging one surface of saidoaintracls to support said pendulum for movement therealong and the lower extremity ofv one of said openings forming a braking portion forengaging the opposite surface of said cam track but normally aintained out of contact therewith andincludlnga contact-making portion disposed at the free end of one of said leg portions; afirst driving member actuated by said tone arm for engaging said pendulum on one side of said one leg. portion in the Vicinity of said opening to advance said pendulum in one direction along said track when said tone arm is displaced in a-given direction; and a l ond. driving member having a contact-i portion normally out'of engagement "w ,h contact-making portion of said lpenduium said second driving'member being mechanically-cone impedereverse movementof said pendul along.

said track and secure firm engagement of sa contact-making portions. f f I f 6, Ina record changer including a tone arm and a relay-actuated control circuit, a relay actuating device comprising: an electrically conductive, elongated cam track; an electrically cenductive, pendulum-like member including a contact-making portion disposed at the free end, a cam-follower portion for engaging one surface of said cam-track to support said pendulum for movement therealong, and a braking portion ior engaging the opposite surface of said cam track but normally maintained out of contact there with; a first driving member actuated by said tone arm for engaging said pendulum in the vicinity of said cam-follower portion to advance said pendulum in one direction along said track when said tone arm is displaced in a given direction; and an electrically conductive, second driving member having a contact-making portion normally out of engagement with said contactmaking portion of said pendulum, said second driving member being mechanically coupled to said tone arm so'that in response" to displacement of said tone arm in a direction reverse to said given direction said second member engages said pendulum to extend said relay circuit through said cam track, said pendulum, both of said contact-making portions and said second driving member and simultaneously to'pivot said pendulum to bring said brake portion into engagement With said cam track thereby to impede reverse movement of said pendulum along said track and secure firm engagement of said contact-making portions.

RALPH A. MULLANEY.

No references cited. 

